Pump surge chamber and secondary liquid feeder



Dec. 26, 1967y R. L. JOHNSON ET; 3,359,909

PUMP `SURGE CHAMBER AND SECONDARY LIQLJID FEEDER Filed June lO, 1965 4Z 68 CONTROL VALVE 1 v 60 PUMP 4/-PUMP ufeGE Ha/#EER AND SECONDARY lau/0 FEEDER Y y y P /N/ENTORS:

- uEsELL oH/vsolv 62 l 65 20 ,0 JOHN @MARR/f) PULSAT/ON HTTORA/Ev/ United States Patent() PUMP SURGE CHAMBER AND SECONDARY LIQUID FEEDER Russell L. Johnson and John D. Harris, Dallas, Tex., as-

signors to John E. Mitchell Company, Dallas, Tex., a corporation of Missouri Filed June 10, 1965, Ser. No. 462,895 2 Claims. (Cl. 10S- 6) This invention relates to a surge chamber and secondary liquid feeder for connection into a pump circuit. The pum-p circuit is one which uses a pulsating pump of any conventional design and which discharges a mixt-ure of a primary liquid and a secondary liquid. Uses for such a pump circuit include car wash machines, chemical spray machines, and others in which a secondary liquid, usually a concentrate, is to be mixed with a primary liquid, such as water. Important results accomplished by the surge chamber and secondary liquid feeder are effective reduc? tion in the amplitude of pulsations on the output from the pump and positive feeding of the secondary liquid.

In the pump circuit, the primary liquid is supplied to the pump inlet. A pipe or hose leads from the pump outlet and has a branch connected to a pumping chamber in the surge chamber and secondary liquid feeder. VAs the pump operates to draw the primary liquid into the pump to force that primary liquid through the outlet from the pump, the changes in outlet pressure are transmitted as pulsations to the pumping chamber. In response to these pulsations, a piston reciprocates in the pumping chamber against the action of the compression spring to relieve some of the surges produced in the outlet pipe of the pump.

A second function of the surge pump and secondary liquid feeder is to positively feed a secondary liquid to the pump inlet for mixture with the primary liquid. A chamber is defined -on the side of the piston opposite the one which is exposed to pump outlet pulsations. This inlet is connected to supply liquid from a secondary liquid source. Reciprocation of the piston drives the secondary liquid through the surge chamber into mixture with the primary liquid being fed to the pump. One-way valves assure that the secondary liquid will flow in only one direction.

The principal object of this invention is to provide a surge chamber and secondary liquid feeder that operates to moderate pulsations in a pumping circuit, and at the same time to positively feed a secondary liquid for mixture with the primary liquid pumped by the pump.

Another ob-ject is t-o provide a surge chamber for a pulsating pump to moderate the pulsations of the pump, wherein the surge chamber has a piston which reciprocates in response to pulsations from the pump, and which itself operates as a secondary pump for a secondary liquid.

Other objects and advantages will be apparent to those skilled in the art.

In the drawing:

FIGURE 1 is a view in longitudinal medial section through the center of the surge chamber and secondary liquid feeder; and

FIGURE 2 is a schematic diagram showing the surge chamber and secondary liquid feeder connected in a pump circuit in which it might typically be used.

Referring now to FIGURE l, the surge chamber and secondary liquid feeder comprises a housing 11 having an inner side wall 12 defining the side wall of a pumping chamber 13 and an inner side Wall 14 defining a spring chamber 15. The pumping chamber 13 and the spring chamber 15 are in coaxial communication with one another.

The housing 11 has an annular flange 16 surrounding ice the pumping chamber end and against the face of which an end cover 17 is held by a plurality of studs 18. An O- ring gasket 19 .provides a fiuid-tight seal. There is a connector extension 20 on the cap 17 having external threads 21 to facilitate the attachment of a hose or pipe, and having a passage 22 through it.

A piston 25 is slidable within the pumping chamber 13 toward and away from the passage 22. The piston 25 has a cylindrical side wall 26 with an O-ring gasket 27 or other sealing means to provide a fluid-tight seal be tween the side o-f the piston 26 and the inner side wall 12 of the pumping chamber 13.

The piston member 25 has a beveled face 28 in its lower side and a recessed spring seat 29 in its upper side.

An opening through the center of the piston member.

28 to provide a fluid-tight seal. A stem 34 extends through` the opening 30 and a snap ring 35 prevents the stem 34l from dropping through the opening 30.

A compression spring 36 bears against the spring seat` 29 and against the upper end of the housing 11 at the upper end of the spring chamber 14. The compression spring biases the piston toward the position shown inV FIGURE 1.

There is a liquid inlet port 40' through the side of the housing 11. The inlet opening 40 is positioned to open into the spring chamber 14. A small valve housing 41 isthreaded int-o a boss 42 surrounding the port 40. Within the val've housing 41, a ball 43` is biased by a compression spring 44 against a valve seat 45 surrounding a valve opening 46. A passage 47 through a hose connection extension 48 communicates with the valve passage 46.

A secondary liquid outlet port 50 extends through the top of the housing 11. A valve seat 51 surrounds the port 50. A small valve housing 52 is threaded into a boss 53 extending upwardly from the housing 11. A ball 54 is biased against the valve seat 51 by a compression Spring 55. An opening 56 leads to the passage 50 and establishes communication with an opening 57 in a hose connection extension 58.

FIGURE 2 shows how the surge chamber and secondary liquid feeder 10 is connected into a pump circuit. In this circuit, a pump i60 of any suitable conventional design has a pipe 61 connected to its'inlet and a pipe I62. connected from its outlet. The pipe 61 is connected through a T 63 to another pipe 64' leading from a source of primary liquid (not shown).'The primary liquid may be any liquid to .be pumped, such as water. The outlet pipe 62 is connected through a T 65 to another pipe 66 leading to an outlet or dispensing nozzle".

Operation In its function in operating as a surge chamber, the surge chamber and secondary liquid feeder 10 receives pulsations through the pipe 67. These pulsations are produced during lthe normal action of the pump 60 which, as it operates, pumps primary liquid from the hose 64 through the pump to the outlet hose 66. The pulsations are transmitted as alternate compression and suction pressures to the face 28 of the piston member 25. During a pumping stroke of the pump 60, pressure against the face 28 of the piston 25 pushes the piston upwardly against the force of the compression spring 36. At this time, the pressure against the head '32 of the poppet valve member 31 presses the beveled `face 33 aga-inst the beveled surface 28 and seals the opening 30;

During an intake stroke of the pump 60, the pressure is reduced against the face of the piston member 25, and the spring 3-6 pushes the piston -member 25 downwardly to the position illustrated in FIGURE 1. This operation continues Arapidly as the pump 60 operates, and the changing volume of the chamber defined by the face 28 of the piston member 25 moderates the pulsat-ions of the pump 60.

As `the piston 25 reciprocates, the secondary liquid is alternately drawn into the spring chamber y14 past the ball valve member 43 and discharged past the ball member -5'4 to the opening 57 and the pipe or hose 71. Thus, on downward movement of the piston member 25, during an intake stroke of the pump 60, a reduced pressure is created in the spring chamber 14 and the pumping chamber 13 above the piston member 25, and liquid from the secondary liquid source 70 presses the ball valve member 43 away from the valve seat 45 and admits secondary liquid into the spring chamber 14 and the pumping chamber 12. This secondary liquid tends to till `the chamber before the piston mem-ber 215 begins an upstroke. When the pumping `stroke of the pump 60 occurs, the piston member 25 moves upwardly, compressing the secondary liquid and closing the ball valve member 43 against the valve seat 45. At the same time, t'he ball valve member 54 is moved upwardly away from its valve seat 51 and the secondary liquid is pumped by the piston mem-ber 25 to the pipe or hose 711 and to the T 63 where the secondary liquid joins with the primary liquid and both are drawn into the pump 60.

The poppet valve 311 operates to purge air from the pumping chamber 12 below the piston member 25. When that position of the chamber is not under pressure, the poppet valve can drop until the snap ring 35 rests against the spring seat 29, and air can be forced from the pumping chamber through the opening '30 into the spring chamber. As soon as the pumping operation 'begins and the pump 60 causes a higher pressure to be established in the pumping chamber l12 below the piston member 25, the poppet valve member 31 is pressed against the beveled surface `28 to close the opening 30. Also, when the pum-p -is not in operation, secondary liquid can iiow through the opening 30 to prime the pumping 4chamber -12 below the piston member 25. Thus, the poppet valve mem-ber eliminates the 'lost time at the beginning of operation normally require-d to purge the chamber of air.

Various changes and modifications may be made within the purview of this invention as will be readily apparent to those skilled in the art. Such changes and modi- 5 cations `are within the scope and teaching of this invention as defined by the claims appended thereto.

What is claimed is:

'1. A liquid mixing system including a primary pump and a secondary pump, the primary pump being of greater capacity than the secondary pump, the secondary pump comprising a surge chamber and secondary liquid feeder including a housing, a pumping chamber within the housing, a spring chamber within the housing, an inlet opening to the pumping chamber, a wall reciprocable within the pumping chamber, means providing 4a liquid seal to block the dow of liquid past the reciprocable wall and to there- 'by block liquid communication between the pumping chamber and the spring chamber, a compression spring within the spring chamber biasing the wall in a direction tending to reduce the volume of the pumping chamber, the primary pump being a pulsating pump having an inlet and an outlet, means to connect the pulsating pump inlet to a source of primary liquid thereby causing the primary liquid to be pumped from the inlet to the outlet of the pulsating pump, means for connecting the inlet opening of the secondary pump to the outlet vfrom the pulsating pump thereby causing the wall to move in response to pulsations of the pulsating pump and dampen surges at the primary pump outlet caused by such pulsations, inlet and outlet ports opening through the secondary pump housing to the spring chamber, means to connect the inlet port to a source of secondary liquid, means to connect the outlet port to the inlet side of the pulsating pump, whereby reciprocations of the wall caused by pulsations of the pulsating pump cause dlow of liquid from lthe secondary liquid source through the spring chamber to the prima-ry pump inlet `for mixture with liquid from the source of primary liquid, and one-Way valve means in the inlet and outlet ports to permit flow in one direction only from the secondary liquid source `toward the pulsating pump inlet,

' the secondary pump deriving its pumping energy solely from the pulsations of the primary pump.

2. The combination of claim 1 wherein the reciprocable wall comprises a piston, an opening through the piston, a valve for alternately opening and closing the opening, the valve having a Valve head responsive to increases in pressure on the piston face side of the piston to close the opening and responsive to decreases in such pressure to open the opening.

References Cited UNITED STATES PATENTS 1,192,274 7/1916 Carney 103-44 1,848,243 3/ 1932 C-onoran 103-7 I2,08 6,173 7/ 1937 'Parker 103-44 2,430,723 11/1947 Lupfer 10S-6 2,543,941 3/1951 Sargent 103-6 3,178,888 4/1965 Hampton 103-9 3,269,3 18 y8/ 1966 Telford et al 103-6 DONLEY I. STOCKING, Primary Examiner. W. L. FR'EEH, Assistant Examiner, 

1. A LIQUID MIXING SYSTEM INCLUDING A PRIMARY PUMP AND A SECONDARY PUMP, THE PRIMARY PUMP BEING OF GREATER CAPACITY THAN THE SECONDARY PUMP, THE SECONDARY PUMP COMPRISING A SURGE CHAMBER AND SECONDARY LIQUID FEEDER INCLUDING A HOUSING, A PUMPING CHAMBER WITHIN THE HOUSING, A SPRING CHAMBER WITHIN THE HOUSING, AN INLET OPENING TO THE PUMPING CHAMBER, A WALL RECIPROCABLE WITHIN THE PUMPING CHAMBER, MEANS PROVIDING A LIQUID SEAL TO BLOCK THE FLOW OF LIQUID PAST THE RECIPROCABLE WALL AND TO THEREBY BLOCK LIQUID COMMUNICATION BETWEEN THE PUMPING CHAMBER AND THE SPRING CHAMBER, A COMPRESSION SPRING WITHIN THE SPRING CHAMBER BIASING THE WALL IN A DIRECTION TENDING TO REDUCE THE VOLUME OF THE PUMPING CHAMBER, THE PRIMARY PUMP BEING A PULSATING PUMP HAVING AN INLET AND AN OUTLET, MEANS TO CONNECT THE PULSATING PUMP INLET TO A SOURCE OF PRIMARY LIQUID THEREBY CAUSING THE PRIMARY LIQUID TO BE PUMPED FROM THE INLET TO THE OUTLET OF THE PULSATING PUMP, MEANS FOR CONNECTING THE INLET OPENING OF 